ISOLATION AND CHARACTERIZATION OF BILIPROTEIN AGGREGATES FROM ACARYOCHLORIS-MARINA, A PROCHLORON-LIKE PROKARYOTE CONTAINING MAINLY CHLOROPHYLL-D

Phycobiliprotein aggregates were isolated from the prokaryote Acaryoch loris marina, containing chlorophyll d as major pigment. In the electr on microscope the biliprotein aggregates appear as rod-shaped structur es of 26.0 x 11.3 nm, composed of four ring-shaped subunits 5.8 nm thi ck and 11.7 nm in diameter. Spectral data indicate that the aggregates contain two types of biliproteins: phycocyanin and an allophycocyanin -type pigment, with very efficient energy transfer from the phycocyani n- to allophycocyanin-type constituent. The chromophore-binding polype ptides of the pigments have apparent molecular masses of 16.2 and 17.4 kDa, They crossreact,vith antibodies against phycocyanin and allophyc ocyanin from a red alga. (C) 1997 Federation of European Biochemical S ocieties.